Plywood

Plywood is an engineered wood panel. It is produced by peeling thin layers of wood called veneers from a log, drying the veneer and then gluing the veneers at alternate angles to each other. As wood is weak in one direction and stronger in the other, the resultant timber is usually stronger than the original.

Plywood is available in a number of grades, sizes, thicknesses and timber types. The end use determines the best plywood to use.

The faces & backs of plywood are usually sorted into 4 main grades, A, B, C & D. ‘A’ face is the highest grade with only very small defects allowable down to ‘D’ grade which can allow open knots and splits. Essentially as you go through the grades from ‘A’ to ‘D’, more imperfections such as knots and splits are acceptable. In many cases a low grade such as ‘D’ is rarely seen as it is usually the bottom of a floor sheet or is against the wall studs in a wall/ceiling application. The most common grade is ‘C’ which is the face grade in CD structural plywood. ‘A’ & ‘B’ faces are usually utilised for their appearance and are often seen in wall and ceiling applications.

Decide if plywood needs to be:

structural or non structural, generally structural (the sheet has a load bearing exerted on it) is more expensive than non-structural

interior or exterior

decorative or non decorative

hardwood or softwood

and the quality of the face required for your particular end use.

The bond (type of glue between layers) also impacts on the price. An A bond is superior to other bonds but may not be necessary for some end uses.

Structural plywood should be “branded” with information relevant to the standard that it meets. If it is not “branded” then it is probably not structural.